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-   -   Nearly Ready To Turn on The Beast (http://www.mechmate.com/forums/showthread.php?t=5509)

metpolbob Tue 07 February 2017 08:25

Nearly Ready To Turn on The Beast
 
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I've managed to get my hands on a used Mechmate... Hoping to drop the machine from its Wheels by the weekend and get things moving :)

sphericos Tue 07 February 2017 14:29

Nice to see another one over here. What are you planning to use it for?

David

metpolbob Wed 08 February 2017 02:49

Hi David, It started off we were going to do some home hobby stuff but the machine was too big for our garage so having needed extra space for storing our stock we've taken on a small unit and put the machine in there. So the short answer is we don't know but are very excited about the opportunities.

Macwood Wed 08 February 2017 03:42

Awesome! Really interested to see how you get on. I am currently renovating a barn so I can start my build in it.
Good luck
Mac

Andrew_standen Fri 10 February 2017 05:08

Another in the UK. ..looks neat Bob.
Did you buy it within the UK?

Many days of fun to be had cutting all sorts of stuff no doubt.

Best regards Andrew ( Mudeford. Dorset )

metpolbob Fri 10 February 2017 08:01

Hi Everyone,

Yep I picked it up from the original builder who wanted more space.

Originally I wanted to build a small 4ft x 4ft table but I couldn't get anyone to weld up the table for me and every engineering company or welding company I approached with the plans said it wasn't for them and passed me on to somewhere else. I think the plans were too professional for them.

I was just about to give up hope and buy a cheap Chinese table top machine when as a last role of the dice I contacted the maker of the machine I now own who had posted on here and now not only is BOB your uncle he's the proud owner of a Mechmate :)

The only downside I have now is that I wasted 700 on buying two sets of laser cut parts :(

Next week I'm hoping to start on the Plenum Vac Bed. All my plumbing supplies have arrived and I've got a couple of Fein Vacs I intend to hook up.

metpolbob Mon 06 March 2017 07:21

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Well I've been trying to cut a Plenum Vac Bed and Failed.

The carriage decided to jump off the rails on the first pass :eek: - But I was more worried about the glowing embers in the wood :)

18mm Birch Cutting to a depth of 12mm in two passes using 12.7mm Straight cutter 120ipm 18000rpm water cooled Chinese spindle.

I had a similar problem at 180ipm on 6mm Chinese Plywood in two passes but put the fail down to the clamps moving and not holding the sheet.

I have to admit that the cut looks pretty rough.

You could see the motors jump when the fail happened.

My first thoughts are that it is the well loved and worn springs.... Any body any thoughts on this. I'm great at CAD but terrible at mechanical and electrical.

Cheers Rob...

bradm Mon 06 March 2017 09:25

That cutter doesn't look good to me. You want something that spirals - could be upcut, downcut, or compression ( both in one ). You're cutting a slot, and there is nowhere for the chips to go, so they're jamming in the slot, getting cut and recut, and then burning and forcing the tool up.

Suggest you start with an upcut. This looks helpful in explaining.

hflwaterski Mon 06 March 2017 09:33

Based on the feed and speed you mentioned, it appears that you are running the router way too fast. I looked up some of the other router manufacturer's charts for hardwood plywood and you should be running a .007-.009 chipload. At 120 ipm with that chipload, and 2 flutes, you should be running 6666 RPM to 8571 RPM. If you're controlling the RPMs manually, then changing the speed would be the first thing I would try. Take a smaller cut to start until it's dialed in. I can't comment and cut quality with straight flutes since I'm always using carbide upcut or downcut bits but I'm pretty sure it shouldn't look that bad. I would check to see if the manufacturer of your particular bit has feed and speed recommendations.

As far as the issue with it jumping the track, it would be good to know at what point it is happening. Is it on the corners? If it is, have you tried slowing down the corner transitions with your CAM software or in Mach 3? Maybe someone else has a better idea on that.

sphericos Mon 06 March 2017 10:03

This might seem like a stupid question but you are running the spindle in the right direction? I have used a 12.7mm two fluted straight cutter on ply , mdf and oak with no great issue. My cut depth was not so great usually no more than 5mm per pass and 12000rpm at around 120ipm. The cutters I use are not as good as yours I get mine from screwfix at 8 a bit as it is less painful when I have to bin them. Mdf in particular seems to destroy the cutting edge.

metpolbob Mon 06 March 2017 11:16

Well..... It's a bit of a School Boy error day for me... It's been several years since I played on a CNC... I will check the Spindle direction tomorrow but I did discover my toolpath was set to climb and not conventional.

I can't see that the direction of travel would affect a cut along the Vector when doing the Vac Bed but I understand it would when I cut shapes such as the circle and square as seen in the pictures... But I will play some more tomorrow.

I've cut several beds previously using the same tooling on various shopbot machines at faster feed rates with good results hence me using the same tool.

I'm looking forward to tomorrow now....

Thank you for all your responses and help...
Rob

Andrew_standen Mon 06 March 2017 11:51

It looks like spindle direction to me, just as David said.
Check that first.
A single flute compression spiral will cut well at 17000 rpm 2500mm with 12mm depth of pass. I use the onsrud 60-152MW.
I don't use many cutters like those in the photo. not on my cnc machine anyway.
Keep us in the loop.
Good luck
regards
Andrew

Tom Ayres Mon 06 March 2017 21:08

Spindle direction would be the first to look at IMHO, new cutter shouldn't have any problems with what you've shown.

metpolbob Tue 07 March 2017 07:45

I'm now making dust :-)
 
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Well a massive big thank you to everyone who has posted.... You were all right about the Spindle turning in the wrong direction.... Two wires swapped and all sorted.

I decided to use the sheet I ruined yesterday for more testing (See Pics)...

The only thing I have noticed is that as the z carriage moved along the y gantry you could see the gantry moving/rocking about 1mm or .5mm along the X rails.

I used the same blade and it seemed to cut through the material pretty easily so I'm putting the movement down to the springs which I am going to replace. Obviously the rack and pinions are well used but don't look like they need replacing just yet.

Once again many thanks for everyone's help..

Bob

hflwaterski Tue 07 March 2017 07:59

Looking much better!

Andrew_standen Tue 07 March 2017 08:38

Well that is good news.
Now your making a real mess ( dust that is ) lol.
What CAM are you using ?
Andrew

metpolbob Tue 07 March 2017 09:09

I already had the Cad drawing from many moons ago.

I exported it from Shopbots Parts Wizard into a very old version of Artcam then into VCarvePro8.5.

The MechMate is running on Mach3

sphericos Tue 07 March 2017 16:05

I did the same thing when I first set my machine up. I wired up the vfd the wrong way round and some how missed the direction of spin. Unfortunately I had nobody here to point out my stupidity so spent several hours scratching my head.

Alan_c Tue 07 March 2017 23:10

If you gantry is moving while cutting in the Y (when it should be stationary) check to see that both X motors are working (i.e. turning under command) Drop one motor and jog in the X direction, if the gantry moves, alternate and do the same for the other side. Check also that the pinions are tight on the motors. I have had it where the one side's pinion was loose and that side was trailing the driven side by a millimeter or so, drove me batty until I found it.

metpolbob Sun 12 March 2017 06:36

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I've replaced the springs which weren't the original Mechmate spec with some more that aren't the Mechmate spec and tightened the pinions which had some movement in them and it's a big improvement but not perfect.

Vac bed all working using two fein vacs and it quite happily holds sheet materials down. I'll post some pics tomorrow and explain what and why I've done certain things.

I went down to the unit with my boss(Her in doors) yesterday to seal the pipe work for the bed and I thought I would cut the 18mm sheet of birch we ruined on the first attempt at the bed. She had other ideas and asked if we could make a house name sign for our new neighbours (good friends) so I said I'd have a go bearing in mind I only had a half inch cutter and only have ever done 2d profiling. The pocketing is 6mm and I profile cut through in 3 passes down to 19mm and left tabs on the first and didn't bother with tabs on the second sign as it wasn't going to move on the vac bed.

We did the first and then she asked me to make a second with the letters better spaced for the size cutter. Hope you like the pics.... and I got a hug from the Neighbours :)

Andrew_standen Sun 12 March 2017 17:07

Looks good.
Will be interested to see how you get along with the hold down set up.
Good luck

hflwaterski Mon 20 March 2017 21:12

Nicely done! Keep up the great work!

metpolbob Thu 23 March 2017 05:32

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Just made some shelving for storage in the unit and the vacuum bed worked great with no problems holding a sheet of bowed Chinese 12mm.

hflwaterski Thu 23 March 2017 06:01

Very cool! Way to go!

Robert M Thu 23 March 2017 06:43

always fun & interesting to see a "new" beast making the builder...happy-er :D
Great jog !!
;)

MarkRH Sat 25 March 2017 03:37

Nice vacuum table, I stopped using Chinese ply that red mystery glue is irritating, even ran into a unit that was 30% moisture.

metpolbob Sat 25 March 2017 05:14

I only used the Chinese for the workshop shelving as it was cheap. Totally agree about the glue and smell. I only intend to use it for prototyping and I will be cutting in Russian Birch.


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